ABSTRACT
The whole philosophy of Descartes is dominated by his pursuit of certainty. Descartes's use of the word 'intuition' to describe human insight might itself be taken as indication of his temerity, for in mediaeval philosophy the term is reserved for the immediate inspection of God and the angels. Unfortunately Descartes had to account somehow for the newly recognized fact of mathematical necessity, and as its origin was clearly not empirical it had to be attributed to a strictly non-sensuous order. The rejection of the evidence of the senses is thus demanded by both of the main factors in Descartes's mental growth. Descartes's problem is to pass from the admitted content of the mind to some metaphysical reality. Now there are peculiarities about Descartes's view of substance which render almost inevitable the conclusion that the self of the 'cogito' is substantial.
